People are often intimidated by the word ‘acid’, especially when it comes to skin. Despite the implication that they may burn or irritate your skin, they can be a very beneficial addition to your skincare if you know how to use them correctly.
Types of acids
There are two main types of acids used in skincare: AHAs and BHAs. AHAs, which stands for alpha hydroxy acid, are a water-soluble acid used to exfoliate the top layers of your skin. They can smooth textured skin, fade dark spots, and reduce signs of ageing. BHAs stands for beta hydroxy acid and are instead an oil-soluble acid. Unlike AHAs, BHAs can penetrate the pores in our skin and gently dissolve dirt, dead skin, and oil to prevent clogged pores and acne. There is also a third skincare acid known as PHAs (Polyhydroxy acids). Like AHAs, they exfoliate the top layer of skin reducing texture irregularities and signs of ageing. The difference between AHAs and PHAs is that PHAs are much larger molecules, meaning that they are only able to exfoliate the very top layer of skin and cannot disturb the deeper layers of the skin, unlike AHAs or BHAs. PHAs are more suitable for people with more sensitive or dry skin as they cause less irritation.
AHAs can be used in cleansers, toners, serums and even moisturisers. Cleansers should be used if you’re trying to avoid irritation as they can be quickly washed off, but if you want more effective and quicker results, use toners and moisturisers as they will exfoliate your skin throughout the day.
Here’s a list of different AHA acids with their pros and cons and recommended products:
Derived from sugar crops, it has a small molecular structure that allows this acid to penetrate deeper into the surface skin (epidermis) than most other AHAs. This means it is more effective at clearing the surface layer of your skin than most AHAs. If you have brown skin, it is important to note that if your skin gets irritated by glycolic acid this can cause deep hyperpigmentation, which can take months or even years to fade. I myself have brown skin and have had no issues using glycolic acid, but if you are someone with sensitive and brown skin, I would highly recommend using a different AHA. Regardless of skin colour, if you’re trying out glycolic acid for the first time, then you should take it slow at first. Try once a week and if your skin doesn’t experience any irritation, then increase regularity. You should only need to use glycolic acid 2-3 times a week.
The Ordinary Glycolic Acid 7% Toning Solution
I personally use this product and cannot recommend it enough. It is not only affordable but effective. It’s great for oily skin, but I would not recommend this to someone with sensitive skin, as it is quite a strong product.
Deciem – £6.80
Boots – £6.80
Can also be found on Amazon and Beauty Bay
Lactic acid used in skincare is derived from milk and fruit sugars. It has a larger molecule size than glycolic acid, so it doesn’t penetrate as deeply into the skin, making lactic acid less irritant to the skin. It’s a good alternative to glycolic acid as it is milder, and I would suggest this AHA to anyone with sensitive skin or who have found glycolic acid to be too harsh. Caution is still advised, as it is still a strong ingredient and should be introduced to your skincare routine slowly.
This acid is derived from bitter almonds and is the AHA most used in anti-ageing products. It is less harsh than glycolic acid and has anti-bacterial properties that can help skin with acne issues.
Like AHAs, BHAs can be used in cleansers, toners, moisturisers, and serums. The main BHA is salicylic acid. This acid penetrates the deeper layers of the skin and the pores to help get rid of blackheads, whiteheads, and other oil-based skin issues. Salicylic acid is one of the main chemicals used to combat acne and can be found in many acne products. As with AHAs, the percentage is important, and if you’re just starting out with salicylic acid, take it slow and start by using products with a lower percentage concentration. Then work your way up, making sure that your skin isn’t getting irritated.
As I said before, PHAs work the same as AHAs, but due to their larger molecular size, they cannot penetrate as deeply into the skin, allowing them to be a lot less irritant. This is a great option for someone with sensitive skin who wants the benefits of AHAs but not the irritation.
The two types of PHAs are lactobionic acid and gluconolactone, which function to gently exfoliate dead skin cells and provide some sun protection as lactobionic acid absorbs free radicals generated by ultraviolet exposure.
Here are some products that contain PHAs:
Many people, including myself, combine AHAs (or PHAs) with BHAs to achieve smooth skin. For oily to normal skin that’s less prone to irritation, you can use acids in a range of products, from cleansers, serums, and moisturisers. I would recommend using a glycolic toner and BHA serum if you are particularly prone to skin build-up and acne, as I am. For people with sensitive or dry skin, I would recommend using minimal amounts of AHAs and BHAs, using them in cleansers and using either lactic acid or even better, PHAs, to reduce the chance of irritation. No matter what your skin type is, stay reasonable and don’t overload your skin with products. Again, take it slow, see what works for your skin, what doesn’t, and make sure to patch test.
In terms of other skincare chemicals, acids are compatible with most but make sure to do your own research. Also, don’t use acids with any type of retinoids (retinol/vitamin A). This combination does not go well together and is known to cause irritation and excessively dry skin. If you are using retinol, either stick to it as many of the benefits of acids and retinol overlap or switch to using acids if retinol is not effective for you.
One of the major drawbacks of using acids is that it makes your skin far more prone to sun damage. This is because as you’re exfoliating older/dead layers of skin, you expose the younger layers of your skin. But those newer/younger layers of skin are now exposed to the sun, which can increase sun damage to the skin and increase the rate of ageing. Even if you’re not using acids in your skincare, it is incredibly important to protect your skin from UVA and UVB damage, so always incorporate sunscreen and SPF into your skincare routine. If you’re using acids, place SPF products after the products containing acids to maximise protection. Even if you have darker skin, using sunblock is still important as it can help prevent hyperpigmentation, and when using possibly irritating products like acids it becomes essential.